This invention relates generally to motors and more particularly to electrical components used with certain motors such as fractional horsepower motors for use with appliance compressors and the like.
It is conventional to mount a motor protector and motor starter in an electricals package for use with a compressor motor. Electrical connections are provided to allow attachment of a run capacitor connected as a separate component. The capacitor can be remotely mounted and connected by suitable leads or the package can be adapted for attachment of the capacitor directly onto the package utilizing a mounting post or the like, as seen for example in U.S. Pat. No. 5,170,307, assigned to the assignee of the present invention, the disclosure of which is incorporated herein by this reference. In either approach, the capacitor and electricals package are purchased as separate components and electrically connected by the appliance manufacturer.
The capacitive element of the run capacitor typically is a thin metallized polymer film which is wound in a coil or stacked in a multilayered structure to provide the needed electrical contact area. The polymer film is mounted in a plastic case and quick connects are attached to wire leads extending to the metallized polymer film which are encapsulated in the plastic case in order to meet industry life and reliability requirements.
The wire leads connected to the metallized polymer film tend to wander causing a change in the specific location of the quick connects. When a manufacturer of the appliance which incorporates a compressor using the electricals package attempts to plug the capacitor quick connects into the connections provided in the electricals package for direct attachment to the package, it is not uncommon for the capacitor quick connects to be out of alignment with the electricals package connectors. This problem is exacerbated by the large offset distance between the capacitor connector post and receptacles. The large offset is necessary to accommodate the wide range of run capacitor geometries for various device applications. This can cause interruptions in the assembly line resulting in lost time. With respect to the use of a discrete or remotely mounted capacitor, separate means must be provided to mount the capacitor using more and longer wire lead lines than desired.
It is an object of the invention to provide a simple, reliable and improved low cost apparatus and method for mounting and electrically connecting a run capacitor to an electricals package containing a motor starter and typically a motor protector. Another object of the invention is to provide an electricals package of the type described in U.S. Pat. No. 5,170,307, identified above, which more efficiently accommodates the run capacitor used with certain motors. Yet another object is the provision of an electricals package which simplifies the electrical connection scheme between a motor starter and a capacitor used therewith. Another object of the invention is to provide an electricals package for a motor starter and a motor protector which also accommodates a capacitor which is less expensive and easier to install by an appliance manufacturer than is the case for prior art devices. Yet another object of the invention is the provision of an apparatus and a method which overcomes the limitations of the prior art noted above.
Briefly, in accordance with the invention, first and second recesses are formed in the package with a motor starter received in the first recess and a run capacitor received and encapsulated in the second recess and with the motor starter thermally isolated from the capacitor and electrically connected to the motor starter terminals. In one preferred embodiment, the electricals package comprises first and second inter-engaging housing members with the first recess formed in the first housing member and the second recess formed in the second housing member. Electrical connection is preferably made to the capacitor through first and second integral connectors, each having a motor starter connecting portion, a motor pin connecting portion and a capacitor lead connecting portion. In one preferred embodiment, each capacitor lead connecting portion includes a pair of spaced apart, parallelly extending rails having a selected length adapted to receive therebetween a respective capacitor lead anywhere along the length of the rails to accommodate lead alignment variations. In another preferred embodiment, each capacitor lead connecting portion includes a quick connect receptacle terminal. According to a feature of the invention, both type of connectors are preferably provided with upper and lower, vertically aligned motor pin connecting portions and capacitor lead connecting portions so that a single connector structure can provide the same connector orientation on either side of the motor starter. The motor starter connecting portion, when used with a disc shaped element of positive temperature coefficient of resistivity (PTC) material, includes spring fingers adapted to be biased against a respective contact face of the element.
In an alternative embodiment, the electricals package comprises a single housing in which recesses are formed for reception of the motor starter and capacitor elements with a lid received over the housing. In all of the embodiments, the capacitor is an integral part of the electricals package rather than a separate component which results in requiring less plastic material than that of the prior art by obviating the need for a separate case and with the capacitor electrically connected to the motor starter terminals so that appliance assembly no longer includes the step of making electrical connections to the capacitor. In accordance with the invention, the electricals package can also serve as the electrical enclosure or terminal cover and is intended for use with fractional horsepower compressors used for refrigerator or related applications, such as dehumidifiers, vending machines and the like.